A medium access control unit such as this, a mobile radio device such as this and a method such as this are known from the UMTS (Universal Mobile Telecommunications System) mobile radio system.
A UMTS mobile radio system normally has a core network (Core Network, CN), a mobile radio access network (UMTS Terrestrial Radio Access Network, UTRAN) and a large number of mobile radio terminals (User Equipment, UE). UMTS provides a transmission mode, referred to as the FDD mode (Frequency Division Duplex), in which signals are transmitted separately in the uplink direction (also referred to as the uplink path which denotes a signal transmission direction from a mobile radio terminal to a respective base station in the mobile radio access network) and in the downlink direction (also referred to as the downlink path, which refers to a signal transmission direction from a base station, which is respectively associated with the mobile radio terminal, in the mobile radio access network to the mobile radio terminal) by means of separate assignment of frequencies or frequency ranges.
UMTS defines an air interface, which is subdivided into three protocol layers, for transmission of data between a mobile radio terminal and a respective base station for a mobile radio cell. An overview and a detailed description of the UMTS air interface protocol layers can be found in 3GPP TS 25.301, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; Radio Interface Protocol Architecture.
The 3GPP standardization committee (3rd Generation Partnership Project) are developing, as described in RP-040081, Proposed Work Item on FDD Enhanced Uplink, TSG-RAN Meeting #23, Phoenix, USA, 10-12 Mar. 2004, an improvement for packet data transmission via the dedicated transport channel DCH (Dedicated Channel) based on UMTS in the uplink direction for the UMTS-FDD mode.
One of the three protocol layers in the UMTS air interface is known as the Radio Resource Control (RRC) protocol layer. The RRC protocol or the RRC protocol layer is responsible for setting up and for clearance, as well as for reconfiguration of physical channels, transport channels, logical channels, signaling radio bearers and radio bearers, and for handling all of the parameters for the UMTS protocol layers for layer 1 and layer 2. For this purpose, the units in the RRC layer in the mobile radio terminal and in the mobile radio network control unit interchange appropriate RRC messages via the signaling radio bearers, as described in 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification.
For management purposes, in general for administration of mobile radio transmission resources in the mobile radio terminal, it is known in the context of uplink packet data transmission for the mobile radio terminal to signal to a mobile radio network control unit (Radio Network Controller, RNC) information about the amount of data traffic in a transport channel, at the RRC protocol layer plane. This is done by means of so-called measurement report messages. As illustrated in Table 1, below, the currently responsible mobile radio network control unit in this context indicates the data buffer storage filling levels, that is to say the filling level of the data buffer storages for the RLC units, for the relevant transport channel. In other words, this means that, in accordance with 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification, the number of data items to be transmitted which are currently located in the buffer storages of the RLC units in the respective mobile radio terminal is transmitted to the mobile radio network monitoring unit at the RRC layer plane.
In this context, the expression mobile radio transmission resources means in particular the transmission power of the mobile radio terminal, the number and the spreading factor of the assigned CDMA codes.
Table 1 shows one example of a measurement result list such as this, as is described in 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification:
TABLE 1InformationElement/GroupType andSemanticsnameNeedMultireferencedescriptionTraffic volumeOP1 tomeasurement<maxRB>results>RB IdentityMPRB Identity10.3.4.16>RLC BufferOPEnumerated (0,In bytes AndPayload4, 8, 16, 32,N Kbytes =64, 128, 256,N*1024 bytes.512, 1024, 2K,Twelve spare4K, 8K, 16K,values are32K, 64K, 128K,needed.256K, 512K,1024K)>Average ofOPEnumerated (0,In bytes AndRLC Buffer4, 8, 16, 32,N Kbytes =Payload64, 128, 256,N*1024 bytes.512, 1024, 2K,Twelve spare4K, 8K, 16K,values are32K, 64K, 128K,needed.256K, 512K,1024K)>VarianceOPEnumerated (0,In bytes Andof RLC Buffer4, 8, 16, 32,N Kbytes =Payload64, 128, 256,N*1024 bytes.512, 1024, 2K,Two spare values4K, 8K, 16K)are needed.
On reception of information such as this, the mobile radio network monitoring unit can use this information to implement appropriate configurations of the mobile radio terminal in order, for example, to increase or to restrict the usable transport formats for a mobile radio terminal, or to carry out a handover to another mobile radio cell, reconfiguration of the dedicated physical channels or an RRC state change, in particular from a first RRC state CELL_DCH to a second RRC state CELL_FACH.
The measurement result list illustrated in Table 1 is thus sent from an RRC unit in the mobile radio terminal to the RRC unit in the corresponding mobile radio network control unit, and the respective RLC data buffer storage filling level is indicated for each radio bearer (RB). The values may be quoted either as an absolute value (RLC Buffer Payload), as an average, value (Average of RLC Buffer Payload), or as a variance from a defined value (Variance of RLC Buffer Payload).
The 3GPP standardization committee is currently working on the improvement of packet data transmission via dedicated transport channels in the uplink path, that is to say for the uplink direction for the UMTS air interface for the FDD mode, in order to increase the data throughput and the transmission rate. For this purpose, a new dedicated transport channel referred to as the Enhanced Dedicated Channel (E-DCH) has been introduced in order to improve the delineation from the already existing dedicated transport channel DCH. The major characteristics of this new transport channel include the use of a Hybrid Automatic Repeat Request method (HARQ) based on the N channel Stop&Wait method, scheduling which is monitored by the base station, which is also referred to in UMTS as NodeB, as well as frame lengths of no more than 10 ms.
The N channel Stop&Wait-HARQ method is a transmission protection method, in which a total of N so-called HARQ processes are configured for one mobile radio terminal, with an HARQ process in each case representing one instance of the Stop&Wait method. The data for each HARQ process is sent to the network and is temporarily stored until the network receives a confirmation that the data has been received correctly (Acknowledgement, ACK). Otherwise, that is to say if the data has not been received correctly (Negative Acknowledgement, NACK), the data is retransmitted to the network.
NodeB monitored scheduling is a method in which the scheduling in the mobile radio terminal, that is to say the selection of an appropriate transport format from a set of defined transport formats for the E-DCH transport channel, is monitored in such a way that the NodeB can temporarily restrict or extend the use of transport formats from the set of defined transport formats for the E-DCH transport channel as a function of the traffic situation in the respective mobile radio cell for a mobile radio terminal.
However, so far, no decisions have yet been made on the details of how the data will be transmitted via the new transport channel E-DCH via a UMTS air interface. One possible solution is to subdivide the data items on the basis of their priorities between different data buffer storages, so-called Priority Queues (PQ), which are then processed with more or less priority corresponding to their importance, and are thus transmitted.
As stated above, a transmission protection method (HARQ) is used, in which the network sends the mobile radio terminal a confirmation that the data has or has not been received correctly. For this function as well, the mobile radio terminal contains different data buffer storages in order to temporarily store the data until correct reception has been acknowledged.
Both functions are carried out within the MAC protocol layer in the newly provided protocol sublayer, that is to say a so-called Medium Access Control Enhanced Uplink (MAC-e) entity, which is present, that is to say implemented, both at the terminal end and at the network end. At the network end, the entity which carries out the communication protocol in accordance with MAC-e is located in the NodeB, that is to say in the UMTS base station.
One important function of the MAC-e protocol sublayer in the mobile radio terminal (subscriber terminal, User Equipment, UE) is to carry out the scheduling of the data to be transmitted for the uplink transmission path (Uplink Direction) on the basis of a transport format selection method, that is to say to select a suitable transport format for the E-DCH transport channel at predetermined defined times as a function of the instantaneously permissible transmission rate, the priority of the data to be transmitted and the available transmission power for the E-DCH transport channel.
The transport format selection method described in 3GPP TS 25.321, Technical Specification, Third Generation Partnership Project, Technical Specification Group Radio Access Network, Medium Access Control (MAC) Protocol Specification, and 3GPP TS 25.133, Technical Specification, Third Generation Partnership Project, Technical Specification Group Radio Access Network, Requirements for Support of Radio Resource Management (FDD), will be explained in more detail in the following text.
A defined number of dedicated transport channels (Dedicated Channels, DCH) are configured on setting up a communication link by the mobile radio network control unit for the mobile radio terminal as a function of the number and the nature of communication services which a mobile radio terminal, or in other words subscriber appliance, is using in the course of transmission of data in the uplink direction. A Transport Format Set (TFS), also referred to as a set of transport formats in the following text, is configured for each transport channel and includes a defined number of transport formats. The permissible combination of transport formats of all DCH transport channels is defined by the so-called Uplink Transport Format Combination Set (TFCS). The MAC-d unit in the mobile radio terminal carries out the scheduling on the basis of the Uplink Transport Format Combination Sets using the transport format combination selection method, that is to say a suitable transport format for each configured transport channel is selected at defined times as a function of the instantaneous transmission rate and the data priority of the logical channels which are mapped onto the respective transport channel, and as a function of the available transmission power in the mobile radio terminal. Details relating to this procedure are described in 3GPP TS 25.321, Technical Specification, Third Generation Partnership Project, Technical Specification Group Radio Access Network, Medium Access Control (MAC) Protocol Specification, and 3GPP TS 25.133, Technical Specification, Third Generation Partnership Project, Technical Specification Group Radio Access Network, Requirements for Support of Radio Resource Management (FDD).
The scheduling method ensures that the data for a communication service is transmitted via the air interface in accordance with its quality of service profile (QoS profile). It also ensures that the transport format combination selection is matched to the respective transmission situation in the mobile radio cell, that is to say only a limited number of transport format combinations are available when the transmission situation is poor, so that the interference produced by the mobile radio terminal itself in the uplink transmission direction remains within limits. In contrast, when the signal transmission situation in the mobile radio cell is good, all of the transport format combinations are normally available, so that the interference which is produced by a mobile radio terminal itself in the uplink transmission direction varies within the allocated quality of service range.
The major characteristics of the transport format combination selection method are:                A status check of the individual transport format combinations within the given transport format combination set is carried out at defined times. On the basis of this status check, one transport format combination may be located in or associated with one of the following states, as is illustrated in the state diagram 700 in FIG. 7:                    a first state 701, which is referred to as a “Supported State”,            a second state 702, which is referred to as an “Excess Power State”, and            a third state 703, which is referred to as a “Blocked State”.                        The status check of the transport format combinations is carried out by means of a power estimate based on the current transmission power and the maximum permissible transmission power of the mobile radio terminal.                    All the transport format combinations which do not satisfy the so-called “Elimination Criterion”, that is to say, in other words, those which require a transmission power which is less than the maximum permissible transmission power, are allocated to the first state 701, that is to say to the “Supported State”. The state changes from the second state 702 or from the third state 703 to the first state 701 are in each case annotated with the reference symbol 704 “Recovery Criterion is met”.            All of the transport format combinations which require a transmission power which is greater than the maximum permissible transmission power are allocated to the second state 702 “Excess Power State”, with the state change from the first state 701 to the second state 702 in FIG. 7 be annotated in FIG. 7 with the reference symbol 705 “Elimination Criterion is met”.            All of the transport format combinations which satisfy the so-called “Blocking Criterion”, that is to say which are in the second state 702 for a defined time period, are allocated to the third state 703 “Blocked State”, with the state change from the second state 702 to the third state 703 being annotated with the reference symbol 706 “Blocking Criterion is met”.                        The only transport format combinations which are taken into account in the transport format combination selection method are those in the first state 701 “Supported State”, in other words the MAC-d unit selects those transport format combinations from the transport format combinations which are in the first state 701 “Supported State”, as a function of the instantaneous transmission rate and of the data priority of the logical channels, and these are mapped onto the individual DCH transport channels. In this case, the logical channels are assigned different priorities from 1 to 8, with a priority of 1 representing the highest priority, and a priority of 8 representing the lowest priority. Those data packets from the logical channels which have a higher priority are given preference in the transport format combination selection method, on the basis of these priorities.        For transport format combinations which are in the second state 702 “Excess Power State” or in the third state 703 “Blocked State”, the status of these transport format combinations is checked continuously. Those transport format combinations which satisfy the so-called “Recovery Criterion”, are then changed once again for the first state 701 “Supported State”, that is to say they can be considered once again in the transport format combination selection method. The state changes are annotated in FIG. 7 with the reference symbol 704 “Recovery Criterion is met”.        Those transport format combinations which are in the second state 702 “Excess Power State” are normally ignored in the transport format combination selection method. One exception to this is the transport format combinations in the so-called “Transport Format Combination Minimum Set” (TFC Minimum Set). The transport format combinations in the TFC Minimum Set, that is to say the transport format combinations in the minimum set, are specified by the mobile radio network control unit RNC and are intended to ensure a minimum guaranteed data transmission rate for the mobile radio terminal. These transport format combinations are thus in any case always taken into account in the transport format combination selection method even if they require a transmission power which is greater than the maximum permissible transmission power in the mobile radio terminal.        
As has been described above, the mobile radio network control unit RNC is responsible for carrying out the mobile radio resource management of all of the mobile radio cells and mobile radio terminals within a mobile radio network subsystem (Radio Network Subsystem, RNS). It is known for the mobile radio network control unit to be able to configure a mobile radio terminal to carry out appropriate measurements in order to allow this to be done.
On the basis of the UMTS mobile radio communication system, the individual measurements which can be carried out by the mobile radio terminal are subdivided into six different types:                intrafrequency measurements,        interfrequency measurements,        intersystem measurements,        quality measurements,        internal measurements, and        measurements for finding the position of the mobile radio terminal.        
Details of the measurements are described in 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification.
As is illustrated in the message flow diagram 800 in FIG. 8, the mobile radio network control unit 801 initiates a specific measurement by sending a so-called measurement control message 802 in the downlink direction to the mobile radio terminal 803, at the RRC protocol plane, via the so-called Signaling Radio Bearers (SRB). This monitoring message 802 informs the mobile radio terminal 803 of when, how and which measurements it should carry out. Once a measurement has been carried out, the mobile radio terminal 803 produces and sends an appropriate so-called measurement report message 804 with the results of the measurement in the uplink direction to the mobile radio network monitoring unit 801.
The mobile radio network monitoring unit 801 can use the information from the measurement report message 804 to implement appropriate configurations for the mobile radio terminal 803, for example to reconfigure the set of transport formats or the dedicated physical channels for the mobile radio terminal 803, or to carry out a handover to another mobile radio cell.
The procedure described on the basis of the prior art for selection of the respectively used transport formats and transport format combinations is highly computation intensive since all the checks and classifications as well as state transitions are carried out in the mobile radio terminal itself, and since the status checks in the mobile radio terminal must always be carried out for all of the transport formats stored in it and transport format combinations stored in it.
Furthermore, the respective status of all of the transport format combinations must be checked, and changed if appropriate, at the respectively predetermined times. This also means a considerable computation time requirement in the mobile radio terminal.
EP 1 341 318 A2 describes a method for controlling the transmission power in an HS-DPCCH (High Speed-Dedicated Physical Control Channel) in a mobile radio terminal. The mobile radio terminal is informed about any transmission power offset, and any transmission power increase in the uplink HS-DPCCH is determined. The transmission power offset is signaled to the NodeB.
WO 2001/47146 A1 describes a method for controlling a mobile radio link between a mobile radio network and a mobile radio terminal. The current transmission power of the mobile radio terminal is taken into account in the course of the allocation of mobile radio resources, and in other mobile radio network operations.
WO 2002/23936 A1 describes a method for optimization of downlink capacities, taking into account the transmission power between a plurality of mobile radio cells. An overload situation in an overloaded mobile radio cell is determined by means of the mobile radio network. An adjacent mobile radio cell in which no overload situation has occurred is identified. Furthermore, a user node which has set up a communication link to the mobile radio network is determined, the downlink data transmission from the overloaded mobile radio cell to the user node is prevented and a downlink data transmission is permitted using a communication link from the mobile radio cell which is not overloaded.
WO 99/43178 A1 describes a method in which different measurement report messages are checked by the mobile radio terminal on the basis of different trigger events in the mobile radio network.
WO 2004/059869 A1 describes a method for selection of transport format combinations. In this method, the physical layer sends a notification message to the MAC protocol layer, which is used to signal when the maximum transmission power for a transmission has been reached.
Document U.S. 2003/0193913 A1 discloses a method for selection of a transport format combination, with classes of transport format combinations being formed, and one class being selected on the basis of a transmission power level.
The document U.S. 2003/0092382 A1 discloses a method for determination of permissible transport format combinations, with a state for each transport format combination being determined on the basis of the transmission power required for that transport format combination, and a selection being made on the basis of the states.
2003/0153313 A1 describes a method for controlling an intersystem handover, in which a mobile radio subscriber is signaled a reduced set of transport format combinations.
The document 2004/0028078 A1 discloses a method for transmission of data packets by means of a radio interface, in which a control unit sends a configuration message and a transport format is selected on the basis of information contained in the configuration message.
WO 03/001681 A1 describes a method for modulation of a radio link, in which a number of channelization codes and a modulation and coding scheme are selected adaptively, and information relating to the selected modulation and coding scheme and the selected number of channelization codes is transmitted to a receiver by means of the radio link.